US3673455A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High speed sensor for initiating circuit breaker tripping
Assignee: General Electric Co
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Filing: 1970-11-18
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Granted: 1972-06-27
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Expires: 1990-11-18
Abstract
Abstract Discloses a high speed sensor for initiating tripping of a transmission-line circuit breaker in response to the occurrence of a fault on the transmission line. Comprises current-magnitude sensing means and rate-of-change of current sensing means that coact to produce sensor operation when the instantaneous magnitude of the line current and its rate of change for a predetermined duration exceed predetermined levels.
Inventors
- 👤 Clyde G Dewey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:19
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/44; H02H3/08; H02H3/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
127 words
A high speed overcurrent sensor for responding to fault conditions in an AC transmission line comprising: a. means for deriving from said line an input signal that is an analog of line current, b. current magnitude sensing means responsive to said input signal for developing a first control signal when the instantaneous value of said line current, irrespective of its instantaneous direction, exceeds a predetermined value, c. rate-of-change sensing means responsive to said input signal for developing a second control signal when the rate-of-change of said line current exceeds a predetermined value for a predetermined duration, d. and an AND circuit responsive to said first and second control signals for developing an output signal in response to the simultaneous presence of said first and second control signals.
Claim 2
Dependent Claim
127 words
A high speed overcurrent sensor for responding to fault conditions in an AC transmission line comprising: a. means for deriving from said line an input signal that is an analog of line current, b. current magnitude sensing means responsive to said input signal for developing a first control signal when the instantaneous value of said line current, irrespective of its instantaneous direction, exceeds a predetermined value, c. rate-of-change sensing means responsive to said input signal for developing a second control signal when the rate-of-change of said line current exceeds a predetermined value for a predetermined duration, d. and an AND circuit responsive to said first and second control signals for developing an output signal in response to the simultaneous presence of said first and second control signals.
Claim 3
Dependent Claim
40 words
The overcurrent sensor of claim 1 in which said rate-of-change sensing means includes a filter that renders said rate-of-change sensing means unresponsive to high rates of change in the line current that prevail for periods shorter Than said predetermined duration.
Claim 4
Dependent Claim
105 words
A high speed overcurrent sensor for responding to fault conditions in an AC transmission line comprising: a. current magnitude sensing means for developing a first control signal when the instantaneous line current, irrespective of its instantaneous direction, through said line exceeds a predetermined magnitude, b. rate-of-change of current sensing means for developing a second control signal when the rate of change of said line current exceeds a predetermined value for a predetermined duration, c. and an AND circuit for receiving said first and second control signals and for developing an output signal in response to the simultaneous reception of said first and second control signals.
Claim 5
Dependent Claim
105 words
A high speed overcurrent sensor for responding to fault conditions in an AC transmission line comprising: a. current magnitude sensing means for developing a first control signal when the instantaneous line current, irrespective of its instantaneous direction, through said line exceeds a predetermined magnitude, b. rate-of-change of current sensing means for developing a second control signal when the rate of change of said line current exceeds a predetermined value for a predetermined duration, c. and an AND circuit for receiving said first and second control signals and for developing an output signal in response to the simultaneous reception of said first and second control signals.
Claim 6
Dependent Claim
49 words
A high speed overcurrent sensor as defined in claim 1 in which the predetermined value of line current that causes said current-magnitude sensing means to operate is greater than the peak current value of traveling waves initiated by a fault occurring at peak normal voltage on said transmission line.
Claim 7
Dependent Claim
59 words
The overcurrent sensor of claim 1 in which: a. said first control signal effectively ceases when the instantaneous value of said line current falls below approximately said predetermined value of line current, and b. said second control signal effectively ceases when said rate of change of said line current falls below approximately said predetermined value of rate of change.
Claim 8
Dependent Claim
59 words
The overcurrent sensor of claim 3 in which: a. said first control signal effectively ceases when the instantaneous value of said line current falls below approximately said predetermined value of line current, and b. said second control signal effectively ceases when said rate of change of said line current falls below approximately said predetermined value of rate of change.
References Cited (Backward Citations)
US3273017A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |